From 6c3f5aef1159a278b54642ebc0bbb5cdab7630cf Mon Sep 17 00:00:00 2001 From: Ivan Vecera Date: Fri, 15 Jan 2016 13:45:28 +0100 Subject: [PATCH] bna: fix Rx data corruption with VLAN stripping enabled and MTU > 4096 The multi-buffer Rx mode implemented in the past introduced a regression that causes a data corruption for received VLAN traffic when VLAN tag stripping is enabled. This mode is supported only be newer chipsets (1860) and is enabled when MTU > 4096. When this mode is enabled Rx queue contains buffers with fixed size 2048 bytes. Any incoming packet larger than 2048 is divided into multiple buffers that are attached as skb frags in polling routine. The driver assumes that all buffers associated with a packet except the last one is fully used (e.g. packet with size 5000 are divided into 3 buffers 2048 + 2048 + 904 bytes) and ignores true size reported in completions. This assumption is usually true but not when VLAN packet is received and VLAN tag stripping is enabled. In this case the first buffer is 2044 bytes long but as the driver always assumes 2048 bytes then 4 extra random bytes are included between the first and the second frag. Additionally the driver sets checksum as correct so the packet is properly processed by the core. The driver needs to check the size of used space in each Rx buffer reported by FW and not blindly use the fixed value. Cc: Rasesh Mody Signed-off-by: Ivan Vecera Reviewed-by: Rasesh Mody Signed-off-by: David S. Miller --- drivers/net/ethernet/brocade/bna/bnad.c | 37 ++++++++++++++++--------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/drivers/net/ethernet/brocade/bna/bnad.c b/drivers/net/ethernet/brocade/bna/bnad.c index 21a0cfc3e7ec..771cc267f217 100644 --- a/drivers/net/ethernet/brocade/bna/bnad.c +++ b/drivers/net/ethernet/brocade/bna/bnad.c @@ -542,39 +542,50 @@ bnad_cq_drop_packet(struct bnad *bnad, struct bna_rcb *rcb, } static void -bnad_cq_setup_skb_frags(struct bna_rcb *rcb, struct sk_buff *skb, - u32 sop_ci, u32 nvecs, u32 last_fraglen) +bnad_cq_setup_skb_frags(struct bna_ccb *ccb, struct sk_buff *skb, u32 nvecs) { + struct bna_rcb *rcb; struct bnad *bnad; - u32 ci, vec, len, totlen = 0; struct bnad_rx_unmap_q *unmap_q; - struct bnad_rx_unmap *unmap; + struct bna_cq_entry *cq, *cmpl; + u32 ci, pi, totlen = 0; + + cq = ccb->sw_q; + pi = ccb->producer_index; + cmpl = &cq[pi]; + rcb = bna_is_small_rxq(cmpl->rxq_id) ? ccb->rcb[1] : ccb->rcb[0]; unmap_q = rcb->unmap_q; bnad = rcb->bnad; + ci = rcb->consumer_index; /* prefetch header */ - prefetch(page_address(unmap_q->unmap[sop_ci].page) + - unmap_q->unmap[sop_ci].page_offset); + prefetch(page_address(unmap_q->unmap[ci].page) + + unmap_q->unmap[ci].page_offset); + + while (nvecs--) { + struct bnad_rx_unmap *unmap; + u32 len; - for (vec = 1, ci = sop_ci; vec <= nvecs; vec++) { unmap = &unmap_q->unmap[ci]; BNA_QE_INDX_INC(ci, rcb->q_depth); dma_unmap_page(&bnad->pcidev->dev, - dma_unmap_addr(&unmap->vector, dma_addr), - unmap->vector.len, DMA_FROM_DEVICE); + dma_unmap_addr(&unmap->vector, dma_addr), + unmap->vector.len, DMA_FROM_DEVICE); - len = (vec == nvecs) ? - last_fraglen : unmap->vector.len; + len = ntohs(cmpl->length); skb->truesize += unmap->vector.len; totlen += len; skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags, - unmap->page, unmap->page_offset, len); + unmap->page, unmap->page_offset, len); unmap->page = NULL; unmap->vector.len = 0; + + BNA_QE_INDX_INC(pi, ccb->q_depth); + cmpl = &cq[pi]; } skb->len += totlen; @@ -704,7 +715,7 @@ bnad_cq_process(struct bnad *bnad, struct bna_ccb *ccb, int budget) if (BNAD_RXBUF_IS_SK_BUFF(unmap_q->type)) bnad_cq_setup_skb(bnad, skb, unmap, len); else - bnad_cq_setup_skb_frags(rcb, skb, sop_ci, nvecs, len); + bnad_cq_setup_skb_frags(ccb, skb, nvecs); rcb->rxq->rx_packets++; rcb->rxq->rx_bytes += totlen; -- 2.30.2